Method for controlling the deformation and encroachment of soft rock

Abstract

This application relates to a method for controlling the deformation limit of soft rock, specifically in the field of tunnel construction, and includes the following steps: S1: Parameter value setting: Determine the allowable deformation T for each step. max Determine the theoretical average deformation rate V of the surrounding rock of each step. 理论平均 S2: Tunnel Excavation: After the bench excavation, a support structure is used to support the surrounding rock, and the actual average deformation rate V of the surrounding rock on the day of construction of the bench is measured. 实际 The actual deformation rate V on day N is obtained. 实际 If V 实际 <V 理论平均 Or if V 实际 =V 理论平均 If V 实际 >V 理论平均 After reinforcing the support structure with a large arch foot structure, the next day's bench excavation is carried out and S2 is repeated until the tunnel construction is completed. This application has the effect of accelerating the construction process while saving production costs.

Description

Technical Field

[0001] This application relates to the field of tunnel construction, and in particular to a method for controlling the deformation and encroachment of soft rock. Background Technology

[0002] During tunnel excavation, it is necessary to ensure the stability of the surrounding rock to prevent safety accidents such as rock collapse. Therefore, after the tunnel is excavated, a support structure will be installed in the tunnel clearance area to prevent the surrounding rock from collapsing.

[0003] However, during the tunneling process, due to geological factors, the surrounding rock may deform and encroach on the tunnel clearance area. Currently, in actual construction, when on-site personnel measure that the surrounding rock deformation has encroached on the tunnel clearance area, it is usually directly judged as a problem of surrounding rock collapse. Other means will be used to further reinforce the support structure to improve the support strength for the surrounding rock.

[0004] However, in the actual process of surrounding rock deformation and encroachment, the encroachment of the surrounding rock does not necessarily lead to the collapse of the surrounding rock. Currently, after the deformation and encroachment of the surrounding rock are identified, the reinforcement measures taken directly on the support structure will not only delay the construction progress but also increase the production cost. Therefore, how to save production costs while speeding up the construction process is an urgent problem to be solved. Summary of the Invention

[0005] In order to accelerate the construction process while saving production costs, this application provides a method for controlling the deformation limit of soft rock.

[0006] The method for controlling the deformation limit of soft rock provided in this application adopts the following technical solution:

[0007] A method for controlling the deformation limit of soft rock includes the following steps:

[0008] S1: Parameter value setting:

[0009] Set the number of steps for multi-stage excavation construction;

[0010] Based on the excavation cycle of each step in the design scheme, the total number of excavation days S and the number of excavation days S1 for each step are obtained.

[0011] Set the total deformation reference value A for the tunnel;

[0012] Let X be the percentage of deformation of each step within the total deformation reference value A;

[0013] According to the formula for calculating deformation: T max =A*X, determine the allowable deformation T for each step. max ;

[0014] Based on the formula: V 理论平均 =T max / S1, determine the theoretical average deformation rate V of the surrounding rock of each step. 理论平均 ;

[0015] S2: Tunnel excavation:

[0016] After the bench excavation, a support structure was used to support the surrounding rock, and the actual average deformation rate V of the surrounding rock on the day of bench construction was measured. 实际 The actual deformation rate V on day N is obtained. 实际 ;

[0017] If V 实际 <V 理论平均 Or if V 实际 =V 理论平均 If so, repeat S2 until the tunnel construction is completed;

[0018] If V 实际 >V 理论平均 Then, after reinforcing the support structure with the large arch foot structure, the next day's step excavation will be carried out and S2 will be repeated until the tunnel construction is completed.

[0019] By adopting the above technical solution, if the surrounding rock deforms during the bench excavation process, the actual deformation rate V will be... 实际 With the theoretical average deformation rate V 理论平均 By comparing the deformation results, it is determined whether further reinforcement of the support structure is needed. Compared with the previous method of reinforcing the support structure as soon as the surrounding rock deforms, this method analyzes the deformation of the surrounding rock. For the support structure within the allowable deformation range, no additional reinforcement is required. This method ensures construction safety, speeds up the construction progress, reduces unnecessary reinforcement structures, and reduces economic costs. In other words, compared with the previous blind reinforcement method, this application determines whether further reinforcement is needed based on actual data, thus achieving precise reinforcement of the surrounding rock.

[0020] Optionally, the total deformation reference value A is the smallest value among the three: the deformation limit required by the owner, the design deformation limit by the design institute, and the deformation limit calculated by the buckling analysis of the arch frame.

[0021] By adopting the above technical solution, and selecting the minimum value among the various constraints, it is possible to ensure that the construction quality meets the needs of all parties.

[0022] The optional support structure includes multiple support sections distributed sequentially along the designed excavation outline of the tunnel, and two adjacent support sections can be detachably connected.

[0023] By adopting the above technical solution and setting up multiple support sections to support the surrounding rock, the stability of the surrounding rock can be improved; at the same time, the split support sections can adapt to tunnels of different shapes.

[0024] Optionally, the large arch foot structure includes:

[0025] A clamping plate having a clamping end and an extending end, the clamping plate clamping and fixing between the ends of two support sections, the clamping end of the clamping plate being located between the two support sections, and the extending end of the clamping plate being located on the side of the support section away from the tunnel clearance zone.

[0026] The reinforcing member has two mounting sidewalls that are perpendicular to each other. One mounting sidewall is fitted and fixedly connected to the extension end of the clamping plate, and the other mounting sidewall is fitted and fixedly connected to the wall surface of the support section on the side away from the tunnel clearance zone.

[0027] By adopting the above technical solution, when the surrounding rock applies pressure to the reinforcing member and the support section towards the tunnel clearance area, the deformation of the two support sections at the connection can be reduced under the action of the reinforcing member and the clamp, thereby being able to withstand greater surrounding rock pressure and ensuring the stability of the surrounding rock.

[0028] Optionally, the two mounting sidewalls form a dihedral angle;

[0029] The reinforcing member has a clearance groove on the side away from the dihedral angle, and a mounting side plate with thickness is formed between the groove wall of the clearance groove and the mounting side wall.

[0030] The clearance groove separates the reinforcing member into two reinforcing ribs in the tunnel depth direction, and the clearance groove is located between the two reinforcing ribs in the tunnel depth direction.

[0031] By adopting the above technical solution and opening the clearance groove, the weight of the reinforcing member can be reduced, while the reinforcing ribs on both sides can ensure the stability of the support.

[0032] Optionally, a connecting plate is fixedly connected to one end of the support section near the clamping plate, and the connecting plate extends to the outer end of the support section in the tunnel depth direction; in the length direction of the support section, the clamping plate is sandwiched between the two connecting plates.

[0033] By adopting the above technical solution, a connecting plate is sandwiched between the clamping plate and the support section, which can further improve the stability of the support structure.

[0034] Optionally, it also includes a reinforcement device, which includes:

[0035] Two reinforcing components, with one reinforcing component corresponding to the sliding connection of each mounting side plate;

[0036] The reinforcing member is perpendicular to the edge of the dihedral along the sliding direction of the mounting side plate;

[0037] Of the two reinforcement components, one is the first reinforcement component and the other is the second reinforcement component;

[0038] Of the two mounting side plates, the mounting side plate that contacts the clamping plate is the first mounting side plate, and the other is the second mounting side plate;

[0039] The first reinforcement component is slidably connected to the first mounting side plate, and the sliding direction is parallel to the mounting side wall of the first mounting side plate;

[0040] The second reinforcement component is slidably connected to the second mounting side plate, and the sliding direction is parallel to the mounting side wall of the second mounting side plate;

[0041] The two reinforcement members slide relative to each other along a third direction, and the angle between the third direction and the sliding direction of each reinforcement member along the mounting side plate is °.

[0042] By adopting the above technical solution, the reinforcement components can be slid along the installation side plate to different positions, which can change the contact area between the reinforcement device and the clamp and support section, thereby providing different support forces for the support section to adapt to different deformation rates of the surrounding rock. Since the reinforcement components need to be oriented towards the inward confinement of the surrounding rock when adjusting them, this process may require resisting the pressure of the surrounding rock. Therefore, the shorter the adjustment interval, the more convenient the operation will be, and it is easier to install compared to directly using large-sized reinforcement components.

[0043] Optionally, the reinforcement includes an inclined portion, the inclined portion being parallel to a third direction, and the inclined portions of the two reinforcements sliding relative to each other along the third direction;

[0044] The inclined portion has a plurality of insertion slots arranged parallel to a third direction at one end near the other inclined portion, and the plurality of insertion slots are spaced apart in the tunnel depth direction; the portion of the inclined portion between two adjacent insertion slots is an insertion portion, and the insertion slot of each inclined portion is used for the insertion portion on the other inclined portion to be inserted in a third direction.

[0045] By adopting the above technical solution, it is possible to prevent the two adjacent inclined sections from shifting in the tunnel depth direction, thereby improving the stability of the reinforcement components.

[0046] Optionally, one of the inclined portions has a guide groove on the inner wall of the insertion slot that is parallel to a third direction, and the other inclined portion has a guide strip protruding from the inner wall of the insertion slot that can be inserted into the guide groove along a third direction.

[0047] By adopting the above technical solution, by inserting the guide strip into the insertion groove, it is possible to prevent the two inclined parts from sliding in a direction perpendicular to the inclined parts, so that the two inclined parts in the insertion state can bear greater surrounding rock pressure.

[0048] Optionally, it also includes a sub-drive component, with each of the reinforcement components connected to the mounting side plate via the sub-drive component; the sub-drive component connected to the first reinforcement component is the first sub-drive component, and the sub-drive component connected to the second reinforcement component is the second sub-drive component, the sub-drive component comprising:

[0049] A guide rod, one end of which is fixedly connected to the reinforcing member to slide synchronously with the reinforcing member, and the other end of which is slidably connected to the mounting side plate; and

[0050] A screw is arranged parallel to the guide rod, with one end of the screw threaded to the guide rod and the other end rotatably connected to the reinforcing member about the screw's own axis.

[0051] By adopting the above technical solution, when adjusting the position of the reinforcement component, simply rotate the screw along the mounting side plate to change the position of the reinforcement component; the screw setting can meet the support requirements of different positions and has high versatility.

[0052] In summary, this application includes at least one of the following beneficial technical effects:

[0053] 1. Compared to the previous approach of reinforcing the support structure whenever the surrounding rock deforms, this application analyzes the deformation of the surrounding rock. For support structures within the allowable deformation range, no additional reinforcement is required. This approach ensures construction safety, accelerates construction progress, reduces unnecessary reinforcement structures, and lowers economic costs. In other words, compared to the previous blind reinforcement methods, this application determines whether further reinforcement is needed based on actual data, achieving precise reinforcement of the surrounding rock.

[0054] 2. By setting up a large arch foot structure, the surrounding rock support can be made more stable;

[0055] 3. By setting reinforcement components, the surrounding rock can be supported with different levels of strength. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of a structure in an embodiment of this application, in which a clamping plate and a reinforcing member are provided between two support sections;

[0057] Figure 2 This is a cross-sectional view of the reinforcing member in an embodiment of this application;

[0058] Figure 3 yes Figure 2Enlarged view of section A;

[0059] Figure 4 This is a schematic diagram of the reinforcement structure in the embodiments of this application;

[0060] Figure 5 This is a cross-sectional view of the reinforcing member and clamping plate in the embodiments of this application, intended to show the structure of the overall drive assembly;

[0061] Figure 6 These are exploded views of two reinforcement components in the embodiments of this application;

[0062] Figure 7 yes Figure 6 Enlarged view of section B;

[0063] Figure 8 This is a schematic diagram of the structure of the sub-drive component and the main drive component in the embodiments of this application;

[0064] Figure 9 This is an enlarged view of part C in section 8.

[0065] Explanation of reference numerals in the attached drawings: 1. Steel arch frame; 11. Support section; 12. Connecting plate; 2. Reinforcing member; 21. Mounting side wall; 22. Clearance groove; 23. Reinforcing rib; 24. Mounting side plate; 24a. First mounting side plate; 24b. Second mounting side plate; 241. Second mounting hole; 25. Mounting plate; 26. Rotating seat; 251. Guide hole; 3. Clamping plate; 31. Clamping end; 32. Extension end; 33. Rotating hole; 34. First mounting hole; 4. Reinforcing member; 4a. First reinforcing member; 4b. Second... Reinforcing components; 41. Vertical part; 42. Inclined part; 421. Insertion slot; 422. Insertion part; 43. Guide bar; 44. Guide groove; 5. Sub-drive assembly; 5a. First sub-drive assembly; 5b. Second sub-drive assembly; 51. Guide rod; 52. Screw; 6. Main drive assembly; 61. First drive shaft; 62. First bevel gear; 63. Second bevel gear; 64. Second drive shaft; 65. Third bevel gear; 66. Fourth bevel gear; 7. Auxiliary support; 71. Telescopic rod; 8. Extension plate. Detailed Implementation

[0066] The following is in conjunction with the appendix Figure 1-9 This application will be described in further detail.

[0067] This application discloses a method for controlling the deformation limit of soft rock. (Refer to...) Figure 1 The method for controlling the deformation limit of soft rock includes the following steps:

[0068] S1: Parameter value setting:

[0069] Set the number of steps for multi-stage excavation construction, such as two-stage excavation method, three-stage excavation method, etc.

[0070] Based on the excavation cycle of each step in the design scheme, the total number of excavation days S and the number of excavation days S1 for each step are obtained.

[0071] The steps to set the total deformation reference value A for the tunnel are as follows:

[0072] First, obtain multiple deformation limits:

[0073] Obtain the deformation limits required by the owner;

[0074] Obtain the design deformation limits from the design institute;

[0075] Obtain the deformation limit values ​​calculated from the buckling analysis of the arch frame;

[0076] Comparing the three deformation limits, the smallest deformation limit is selected as the total deformation reference value A;

[0077] Based on the parameters provided by the design institute, the proportion of deformation of each step within the total deformation reference value A is set as X;

[0078] According to the formula for calculating deformation: T max =A*X, determine the allowable deformation T for each step. max ;

[0079] Based on the formula: V 理论平均 =T max / S1, determine the theoretical average deformation rate V of the surrounding rock of each step. 理论平均 ;

[0080] S2: Tunnel excavation:

[0081] After the bench excavation, a support structure was used to support the surrounding rock, and the actual average deformation rate V of the surrounding rock on the day of bench construction was measured. 实际 The actual deformation rate V on day N is obtained. 实际 ; V each day 实际 With V 理论平均 To make a comparison,

[0082] If V 实际 <V 理论平均 or V 实际 =V 理论平均 If S2 is repeated, the next day's step excavation will continue until the tunnel construction is completed.

[0083] If V 实际 >V 理论平均 Then, after reinforcing the support structure with the large arch foot structure, the next day's step excavation will be carried out and S2 will be repeated until the tunnel construction is completed.

[0084] Reference Figure 1In some embodiments, the support structure includes a steel arch frame 1, which includes multiple support sections 11 distributed sequentially along the tunnel design excavation outline. The support sections 11 are preferably I-beams, and two adjacent support sections 11 can be detachably connected. If it is necessary to reinforce the support structure, a large arch foot structure is added to the outer side of the steel arch frame 1 near the ground.

[0085] The large arch foot structure is located between two adjacent support sections 11. The large arch foot structure includes a reinforcing member 2 and a clamping plate 3 with a clamping end 31 and an extension end 32. Along the direction of the steel arch frame 1, the clamping plate 3 is fixedly clamped between two adjacent support sections 11, and the support section 11 is set perpendicular to the clamping plate 3. It should be understood that since the support section 11 may have a certain curvature on the tunnel excavation outline, the aforementioned setting of the support section 11 perpendicular to the clamping plate 3 should be understood as the tangent of the support section 11 where it connects to the clamping plate 3 being perpendicular to the clamping plate 3.

[0086] To improve the firmness of the connection between the support section 11 and the clamping plate 3, a connecting plate 12 perpendicular to the support section 11 is welded to the end wall of the support section 11. The two ends of the connecting plate 12 extend to the outside of the support section 11 in the tunnel depth direction. In the horizontal and perpendicular direction of the tunnel depth, the two side walls of the connecting plate 12 are flush with the inner and outer walls of the support section 11 respectively. The clamping plate 3 is clamped between the two connecting plates 12, and the clamping plate 3 is fixedly connected to the two connecting plates 12 by high-strength bolts.

[0087] Reference Figure 1 The length of the clamping plate 3 in the tunnel depth direction is the same as the length of the connecting plate 12 in the tunnel depth direction, so that the two end walls of the clamping plate 3 are coplanar with the end walls of the connecting plate 12 respectively; in the direction of the steel arch frame, the clamping end 31 of the clamping plate 3 is located between the two connecting plates 12, and the extension end 32 of the clamping plate 3 extends to the side of the support section 11 away from the tunnel clearance zone.

[0088] Reference Figure 2 and Figure 3 The reinforcing member 2 is located on the side of the clamping plate 3 near the tunnel arch, and on the side of the support section 11 away from the tunnel clearance zone. The reinforcing member 2 has two mounting sidewalls 21, which are perpendicular to each other to form a dihedral angle. Of the two mounting sidewalls 21, one mounting sidewall 21 is fitted and fixedly connected to the extension end 32 of the clamping plate 3, and the other mounting sidewall 21 is fitted and fixedly connected to the wall surface of the support section 11 away from the tunnel clearance zone. In this disclosure, the reinforcing member 2 is fixedly connected to the extension end 32 of the clamping plate 3 by welding and to the support section 11 by high-strength bolts.

[0089] The reinforcing member 2 has a clearance groove 22 on one side of the 90° included angle of the dihedral angle. In the tunnel depth direction, the clearance groove 22 divides the reinforcing member 2 into two reinforcing ribs 23, that is, the two reinforcing ribs 23 are distributed at intervals in the tunnel depth direction, and the clearance groove 22 is located between the two reinforcing ribs 23. At the same time, the other two side walls of the clearance groove 22 each form an installation side plate 24 with thickness between them and an installation side wall 21. The installation side plate 24 that contacts the clamping plate 3 is the first installation side plate 24a, and the installation side plate 24 that contacts the support section 11 is the second installation side plate 24b.

[0090] Reference Figure 4 and Figure 5 In some embodiments of this application, a reinforcement device is also included. The reinforcement device includes a reinforcement component 4, a sub-drive component 5 and a main drive component 6. There are two reinforcement components 4 and two sub-drive components 5. Each sub-drive component 5 is connected to one reinforcement component 4. The main drive component 6 is used to drive the two sub-drive components 5 to run.

[0091] Reference Figure 5 Of the two reinforcement components 4, one is the first reinforcement component 4a and the other is the second reinforcement component 4b. The first reinforcement component 4a is slidably connected to the first mounting side plate 24a, and the sliding direction is parallel to the first direction. The second reinforcement component 4b is slidably connected to the second mounting side plate 24b, and the sliding direction is parallel to the second direction. The second direction is the tangent direction at the location where the second reinforcement component 4b is located in the support section 11. The first direction is perpendicular to both the tunnel depth direction and the second direction. The first reinforcement component 4a and the second reinforcement component 4b slide relative to each other along a third direction. The third direction is perpendicular to the tunnel depth direction, and the third direction forms a 45° angle with both the first and second directions. Therefore, during the process of sliding the two reinforcement components 4 along the mounting side plate 24, the total length formed by the cooperation of the two reinforcement components 4 in the third direction can be changed, thereby providing different support forces.

[0092] Reference Figure 6 and Figure 7 In this disclosure, the reinforcement 4 includes an integrally formed vertical portion 41 and an inclined portion 42. The vertical portion 41 of the first reinforcement 4a is perpendicular to the first direction, and the vertical portion 41 of the second reinforcement 4b is perpendicular to the second direction. The inclined portion 42 is located on the side where the vertical portions 41 of the two reinforcements 4 are close to each other. Each inclined portion 42 has a insertion groove 421 at one end away from the vertical portion 41 along a third direction. The insertion groove 421 is parallel to the third direction. The portion of each inclined portion 42 between two adjacent insertion grooves 421 is an insertion portion 422. When the two inclined portions 42 slide relative to each other along the third direction, the insertion groove 421 on each inclined portion 42 is used for the insertion portion 422 on the other inclined portion 42 to be inserted along the third direction.

[0093] The inclined portion 42 has a guide strip 43 protruding from the side wall of the insertion portion 422, which is parallel to the third direction. The inclined portion 42 has a guide groove 44 parallel to the third direction on the inner wall of the insertion groove 421. The guide groove 44 on each inclined portion 42 is used for the insertion of the guide strip 43 on another inclined portion 42, so that the guide strip 43 can slide in the guide groove 44 along the third direction. After the guide strip 43 is inserted into the guide groove 44, the guide strip 43 makes appropriate contact with the inner wall of the guide groove 44. Through the contact between the guide strip 43 and the inner wall of the guide groove 44, the pressure exerted by the surrounding rock on the inclined portion 42 in the direction perpendicular to the third direction can be resisted. Therefore, the pressure bearing capacity of the reinforcement device can be adjusted by adjusting the sliding of the two reinforcement parts 4 in the third direction.

[0094] Reference Figure 8 In order to install the sub-drive assembly 5, in some embodiments of this application, a mounting plate 25 is fixedly connected to the reinforcing member 2, and a mounting plate 25 is fixedly connected to each mounting side plate 24. One end of the mounting plate 25 extends into the relief groove 22, and a sub-drive assembly 5 is connected to each mounting plate 25. The sub-drive assembly 5 is used to drive the reinforcing member 4 to move along the reinforcing member 2. The sub-drive assembly 5 connected to the first reinforcing member 4a is the first sub-drive assembly 5a, and the sub-drive assembly 5 connected to the second reinforcing member 4b is the second sub-drive assembly 5b.

[0095] The drive assembly 5 includes a guide rod 51 and a screw 52. The guide rod 51 is directly or indirectly slidably connected to the reinforcing member 2. In this disclosure, a guide hole 251 is provided on the mounting plate 25 for the guide rod 51 to pass through. The guide rod 51 passes through the guide hole 251 so that the guide rod 51 slides along the reinforcing member 2 by sliding on the mounting plate 25. The cross-sections of the guide rod 51 and the guide hole 251 are non-circular to prevent the guide rod 51 from rotating in the guide hole 251. Preferably, the cross-sections of the guide rod 51 and the guide hole 251 in this disclosure are rectangular. One end of the guide rod 51 is fixedly connected to the reinforcing member 4, and the other end extends into the clearance groove 22 after passing through the guide hole 251 on the mounting plate 25.

[0096] Specifically, the guide rod 51 in the first sub-drive assembly 5a is slidably connected to the mounting plate 25 along the first direction, and the guide rod 51 in the second sub-drive assembly 5b is slidably connected to the mounting plate 25 along the second direction;

[0097] In the drive assembly 5, the screw 52 is set parallel to the guide rod 51. The screw 52 is located in the relief groove 22, and one end of the screw 52 is threaded to the guide rod 51, while the other end is rotatably connected to the reinforcing member 2. During the rotation of the screw 52 around its own axis, the guide rod 51 will move along its own length direction due to the limiting effect of the inner wall of the guide hole 251 on the guide rod 51. Thus, the reinforcing member 4 can be moved by the guide rod 51. In order to install the screw 52, ​​the reinforcing member 2 has a rotating seat 26 protruding from the inner wall of the relief groove 22. The end of the screw 52 away from the reinforcing member 4 is rotatably connected to the rotating seat 26.

[0098] Reference Figure 8 and Figure 9 The main drive assembly 6 is used to drive the screws 52 in the two sub-drive assemblies 5 to rotate synchronously. The main drive assembly 6 includes a first drive shaft 61, a first bevel gear 62, a second bevel gear 63, a second drive shaft 64, a third bevel gear 65, and a fourth bevel gear 66. In this disclosure, the first bevel gear 62, the second bevel gear 63, the third bevel gear 65, and the fourth bevel gear 66 are all 45° bevel gears.

[0099] The first drive shaft 61 is parallel to the first direction. A rotating hole 33 is provided in the clamping plate 3 along the first direction. The rotating hole 33 penetrates the end wall of the clamping end 31 of the clamping plate 3. One end of the first drive shaft 61 is located in the rotating hole 33 and can rotate around its own axis in the rotating hole 33. The other end passes through the end wall of the clamping end 31 and extends to the outside of the clamping plate 3. A first mounting hole 34 communicating with the rotating hole 33 is also provided in the clamping plate 3. In this disclosure, the first mounting hole 34 penetrates the clamping plate 3 along the second direction.

[0100] The first bevel gear 62 is located in the first mounting hole 34 and is coaxially fixedly connected to the first drive shaft 61 so that the first bevel gear 62 can rotate with the first drive shaft 61; the second bevel gear 63 is located in the first mounting hole 34 and meshes with the first bevel gear 62 so that the second bevel gear 63 rotates with the first bevel gear 62.

[0101] The first mounting side plate 24a has a second mounting hole 241 that communicates with the first mounting hole 34 through it along the second direction. One end of the second drive shaft 64 is coaxially fixedly connected to the second bevel gear 63, and the other end passes through the second mounting hole 241 and extends into the relief groove 22. The second bevel gear 63 is rotatably connected to the reinforcing member 2 through a bearing so that the second drive shaft 64 rotates with the second bevel gear 63 around its own axis.

[0102] The third bevel gear 65 is coaxially fixedly connected to the screw 52 in the second sub-drive assembly 5, and coaxially fixedly connected to the second drive shaft 64, so that the third bevel gear 65 and the second bevel gear 63 are coaxial; the fourth bevel gear 66 is coaxially fixedly connected to the screw 52 in the first sub-drive assembly 5, and the third bevel gear 65 and the fourth bevel gear 66 mesh.

[0103] As the first drive shaft 61 rotates along the clamping plate 3, the first bevel gear 62 rotates synchronously with the first drive shaft 61. Under the meshing action of the first bevel gear 62 and the second bevel gear 63, the first bevel gear 62 will drive the second bevel gear 63 to rotate synchronously; the second drive shaft 64 and the third bevel gear 65, which are coaxially fixedly connected to the second bevel gear 63, will rotate synchronously; and the fourth bevel gear 66, which meshes with the third bevel gear 65, will rotate synchronously.

[0104] During the rotation of the third bevel gear 65 and the fourth bevel gear 66, the screws 52 in the two sub-drive components 5 will rotate synchronously. The screws 52 will then drive the guide rod 51 to slide along the mounting plate 25, thereby changing the distance between the reinforcement 4 and the reinforcing member 2. During the sliding of the two reinforcement members 4 in the third direction, the support range of the clamping plate 3 and the support section 11 can be changed, thereby changing the support force.

[0105] Reference Figure 8 To further enhance the support strength, in some embodiments of this application, an auxiliary support 7 is also included. The auxiliary support 7 includes a telescopic rod 71. In this disclosure, the vertical part 41 of the first reinforcement 4a is fixedly connected to an extension plate 8. The extension plate 8 extends to the side of the extension end 32 of the clamping plate 3 away from the clamping end 31. The telescopic direction of the telescopic rod 71 is parallel to the first direction. One end of the telescopic rod 71 is fixedly connected to the clamping plate 3, and the other end is fixedly connected to the extension plate 8. Thus, the reinforcement 4 and the clamping plate 3 can work together to support the support section 11.

[0106] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for controlling the deformation and encroachment limit of soft rock, characterized in that, Includes the following steps: S1: Parameter value setting: Set the number of steps for multi-stage excavation construction; Based on the excavation cycle of each step in the design scheme, the total number of excavation days S and the number of excavation days S1 for each step are obtained. Set the total deformation reference value A for the tunnel; Let X be the percentage of deformation of each step within the total deformation reference value A; According to the formula for calculating deformation: T max =A*X, determine the allowable deformation T for each step. max ; Based on the formula: V 理论平均 =T max / S1, determine the theoretical average deformation rate V of the surrounding rock of each step. 理论平均 ; S2: Tunnel excavation: After the bench excavation, a support structure was used to support the surrounding rock, and the actual average deformation rate V of the surrounding rock on the day of bench construction was measured. 实际 The actual deformation rate V on day N is obtained. 实际 ; If V 实际 <V 理论平均 Or if V 实际 =V 理论平均 If so, repeat S2 until the tunnel construction is completed; If V 实际 >V 理论平均 Then, after reinforcing the support structure with the large arch foot structure, the next day's step excavation will be carried out and S2 will be repeated until the tunnel construction is completed. The support structure includes multiple support sections (11) arranged sequentially along the designed excavation outline of the tunnel, and adjacent support sections (11) are detachably connected. The large arch foot structure includes: A clamping plate (3) having a clamping end (31) and an extension end (32) clamps and fixes between the ends of two support sections (11). The clamping end (31) of the clamping plate (3) is located between the two support sections (11), and the extension end (32) of the clamping plate (3) is located on the side of the support section (11) away from the tunnel clearance zone. The reinforcing member (2) has two mounting sidewalls (21) that are perpendicular to each other. One of the mounting sidewalls (21) is fitted and fixedly connected to the extension end (32) of the clamp (3), and the other mounting sidewall (21) is fitted and fixedly connected to the wall surface of the support section (11) away from the tunnel clearance area. The two mounting sidewalls (21) form a dihedral angle; The reinforcing member (2) has a relief groove (22) on the side away from the dihedral angle, and a mounting side plate (24) with thickness is formed between the groove wall of the relief groove (22) and the mounting side wall (21). The clearance groove (22) separates the reinforcing member (2) into two reinforcing ribs (23) in the tunnel depth direction, and the clearance groove (22) is located between the two reinforcing ribs (23) in the tunnel depth direction; It also includes a reinforcement device, which includes: Two reinforcing members (4), each of the mounting side plates (24) has a corresponding sliding connection of one of the reinforcing members (4); The reinforcing member (4) is perpendicular to the edge of the dihedral along the sliding direction of the mounting side plate (24); Of the two reinforcement components (4), one is the first reinforcement component (4a) and the other is the second reinforcement component (4b); Of the two mounting side plates (24), the mounting side plate (24) that contacts the clamping plate (3) is the first mounting side plate (24a), and the other is the second mounting side plate (24b); The first reinforcement member (4a) is slidably connected to the first mounting side plate (24a), and the sliding direction is parallel to the mounting side wall (21) of the first mounting side plate (24a); The second reinforcement member (4b) is slidably connected to the second mounting side plate (24b), and the sliding direction is parallel to the mounting side wall (21) of the second mounting side plate (24b); The two reinforcement members (4) slide relative to each other along a third direction, and the angle between the third direction and the sliding direction of each reinforcement member (4) along the mounting side plate (24) is 45°. The reinforcement member (4) includes an inclined portion (42) which is parallel to a third direction, and the inclined portions (42) of the two reinforcement members (4) slide relative to each other along the third direction; The inclined portion (42) has a plurality of insertion slots (421) arranged parallel to the third direction at one end near the other inclined portion (42), and the plurality of insertion slots (421) are spaced apart in the tunnel depth direction; the portion of the inclined portion (42) between two adjacent insertion slots (421) is an insertion portion (422), and the insertion slot (421) of each inclined portion (42) is used for the insertion portion (422) on the other inclined portion (42) to be inserted along the third direction.

2. The method for controlling the deformation and encroachment of soft rock according to claim 1, characterized in that, The total deformation reference value A is the smallest value among the three: the deformation limit required by the owner, the design deformation limit of the design institute, and the deformation limit calculated by the buckling analysis of the arch frame.

3. The method for controlling the deformation and encroachment of soft rock according to claim 2, characterized in that, A connecting plate (12) is fixedly connected to one end of the support section (11) near the clamping plate (3). In the tunnel depth direction, the connecting plate (12) extends to the outer end of the support section (11). In the length direction of the support section (11), the clamping plate (3) is clamped between the two connecting plates (12).

4. The method for controlling the deformation and encroachment of soft rock according to claim 3, characterized in that, One of the inclined portions (42) has a guide groove (44) on the inner wall of the insertion groove (421) that is parallel to the third direction, and the other inclined portion (42) has a guide strip (43) protruding from the inner wall of the insertion groove (421) that can be inserted into the guide groove (44) in the third direction.

5. The method for controlling the deformation and encroachment of soft rock according to claim 4, characterized in that, It also includes a sub-drive assembly (5), each of the reinforcement members (4) being connected to the mounting side plate (24) via the sub-drive assembly (5); the sub-drive assembly (5) connected to the first reinforcement member (4a) is the first sub-drive assembly (5a), and the sub-drive assembly (5) connected to the second reinforcement member (4b) is the second sub-drive assembly (5b), the sub-drive assembly (5) comprising: Guide rod (51), one end of which is fixedly connected to the reinforcing member (4) to slide synchronously with the reinforcing member (4), and the other end is slidably connected to the mounting side plate (24); and A screw (52) is arranged parallel to the guide rod (51). One end of the screw (52) is threaded to the guide rod (51), and the other end is rotatably connected to the reinforcing member (2) around the axis of the screw (52).

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